1. Activity at the Summit Crater: After its peak between 11 and 18 July 2026, eruptive activity at Mayon’s summit crater has declined based on the decreasing record of Strombolian events, lava effusion and lava collapse-fed rockfall and pyroclastic density currents or PDCs. The downslope advance of active lava flows on the Mi-isi, Bonga and Basud Gullies halted at respective radial distances of 2.7 kms, 3.2 kms and 3.8 kms from the summit crater on 22 July 2026, indicating a cessation of supply of fresh magma from the crater in this period. Subsequently, lava collapse-fed rockfall decreased from an average of 278 events/day from the start of eruption on 6 January 2026 to 12 events/day from 23 July 2026 as lava flows began stabilizing in place and shedding less and less material onto the volcano slopes. Discrete Strombolian and PDC activity have likewise ceased after the last recorded events on 26 and 28 July 2026. To date, the volume of erupted lava including rockfall and PDC deposits totals approximately 89 million m³.
2. Seismic Activity: Volcanic earthquakes generated by Strombolian activity, magma extrusion, degassing and occasional rock-fracturing beneath the edifice have diminished from a monthly average of 57 events/day since 6 January 2026 to 13 events/day since 23 July 2026. Real-time seismic energy release from the volcano or RSAM has also returned to pre-eruption levels. These seismic parameters are consistent  with  the observed decline in surface (lava flow, lava collapse-fed rockfall and PDC) activity and likewise reflect the cessation of magma supply to the summit crater.
3. Volcanic Degassing: Volcanic SO₂ emission obtained by campaign mobile DOAS and stationary ScanDOAS measurements peaked at a record average of 13,128 tonnes/day on 11 July 2026 prior to the onset of peak Strombolian activity, but has decreased since. Average SO₂ emission from the onset of eruption on 6 January 2026 averages 2,450 tonnes/day while emission since 23 July 2026 (after the cessation of magma supply) averages 2,163 tonnes/day. The decreased but sustained levels of volcanic degassing indicate that while magma supply to the summit crater may have ceased, batches of magma continue to be periodically intruded in storage beneath the edifice, consistent with ground deformation and microgravity data.
4. Ground Deformation and Microgravity: Long-term ground deformation data from Global Positioning System (GPS), Electronic Distance Measurements (EDM) and electronic tilt measurements indicate that the volcanic edifice has remained generally asymmetrically inflated since January 2025. A short-term net deflation has been recorded in the eastern sector since the onset of eruption on 6 January 2026. Consistent with this net deflation, long- and short-term campaign microgravity measurements likewise suggest mass density decreases across the Mayon edifice, and magma drainage beneath the east to northeast flanks of the volcano in particular, where microgravity anomalies between -150 to -320 microgals were recorded between March and June 2026. Nonetheless, the overall ground deformation and microgravity parameters suggest that while the edifice has been depressurized due to shallow magmatic eruption processes, the Mayon edifice remains generally pressurized with respect to background conditions.

 

In view thereof, DOST-PHIVOLCS is lowering the Alert Level of Mayon Volcano from Alert Level 3 (magmatic unrest / increased tendency towards hazardous eruption) to Alert Level 2 (moderate level of unrest). However, the lowering of the alert status should not be interpreted to mean that the volcano’s unrest has ceased, considering that the edifice is still pressurized and SO₂ emission remains high relative to baseline levels. The public is strongly advised to be vigilant and refrain from entering the six (6) kilometer-radius Permanent Danger Zone (PDZ) to minimize risks from sudden minor explosions or phreatic eruptions that could general volcanic hazards such as short-range PDCs, rockfall, ballistics projectiles and landslides. Thin ashfall could also be experienced downwind of the Mayon edifice in the event of minor explosions, phreatic eruptions or lava collapse-fed PDCs. Given the large amounts of volcanic material deposited by the 2026 eruption, heavy to intense rainfall could generate post-eruption lahars and sediment-laden streamflow in channels draining the Mi-isi, Bonga and Basud Gullies. Communities and local government units along these lahar channels as well as along channels of perennial lahar hazards must be vigilant and ready to evacuate in the event heavy or intense rainfall on the volcano slopes that could potentially generate life-threatening lahars and sediment-laden streamflow. Civil aviation authorities must also advise pilots to avoid flying close to the volcano’s summit as ash from any sudden eruption can be hazardous to aircraft. DOST-PHIVOLCS maintains close monitoring of Mayon Volcano and any new development will be communicated to all concerned stakeholders.

 

DOST-PHIVOLCS